----Distributed to -------- KEKVAX::NISHIKAW, KEKVAX::CHIKAMAT, kekux::"miyamoto@ieux01.ins.u-tokyo.ac.jp", kekvax::kenzo, KEKVAX::SAKUDA, kekvax::kanzaki, KEKVAX::OYAMAY, KEKVAX::SOSAMU, KEKVAX::MINORU, KEKPSA::ieiri, KEKUX::"miyano@ngthep.hep.sc.niigata-u.ac.jp", kekvax::tamuran, KEKUX::"SOBEL@MASTER.PS.UCI.EDU", kekvax::gajewski, kekux::"chiaki@sbhep.physics.sunysb.edu", kekux::"totsuka@jpnutins.bitnet", kekux::"suzuki@sukip03.icrr.u-tokyo.ac.jp", kekux::"itow@suketto.icrr.u-tokyo.ac.jp", kekux::"sakai@icrr.u-tokyo.ac.jp", kekux::"kajita@jpnutins.bitnet", kekux::"nakahata@icrr.u-tokyo.ac.jp", KEKUX::"kajino@konansun2.kek.jp", kekvax::suzukia, kekux::"kaneyuki@phys.titech.ac.jp", kekux::"thara@kobe-u.ac.jp", kekux::"aoki@kobe-u.ac.jp", KEKUX::"SUZUKI@PHYS01.PHYS.KOBE-U.AC.JP", KEKVAX::NIWA -------------------------- E362 (Neutrino Oscillation) MEETING MEMO Date: 15:30-16:00, October 6, 1995 Place: KEK Minami-tateya Present: Nishikawa (Chairman), Chikamatsu, Miyamoto (INS), Ohyama, Sakuda (KEK), Tamura (Okayama), Nishijima, Etou (Toukai), (1) Nishikawa write down the subjects to be discussed at today's meeting. (a) 1 kton tank detector. (b) Schedule for dismounting VENUS muon chambers and muon filters. Schedule for dismounting TOPAZ lead-glass counters. (c) What to do with water/SCIFI detector next year. (d) Application for Grant-in-Aid for Scientific Research from Japan Ministry of Education, Science and Culture (so called Kakenhi). (2) 1 kton detector The problems with 1kton detector are that it cannot measure muon energy above 1 GeV and that it cannot define the fiducial volume of the neutrino interactions (error=+-50 to 60%). (a) Nishikawa suggests that it can be used to measure the ratio of the single muon events to the total charged-current (CC) events (1 muon + anything). Single muon events consist of quasi-elastic events (QE) and CC 1-pion (pi+) production with p<250 MeV/c (below Cherenkov threshold). Thus, the measurement of the ratio would give the fraction of 1-pion production with p<250 MeV/c in quasi-elastic event sample experimentally and help the analysis of Super Kamiokande. According to the Monte Carlo, the contamination of 1-pion production with p<250 MeV/c in the quasi-elastic event sample is estimated to be about 30%. (Discussion): If deadtime-less electronics works as designed at SK, pi+'s below Cherenkov threshold can be identified with better efficiency than 50%. For example, pi+ ->mu+ -> e+ decay probability 90% times electron identification efficiency 90% makes 80%. So, the 1-pion contamination in the QE event sample can be reduced to 15% or even to 6%. This is good enough. Further, Sakuda argues that one must prove that the errors of +-50% or so really cancell in the ratio measurement, where both the numerator and denominator have 50-60% errors due to poor fiducial volume definition and that it would give a result with a few % accuracy. (b) Nakamura says that one source of the background to the proton decays at SK is the neutrino interactions due to atmospheric neutrinos and that we can study the neutrino interactions using neutrino beams and 1kton detector. Ohyama is asked to study these problems (a-b). He stresses that we need automatic 1-ring reconstruction program. We hear that Koshio has a Monte Carlo to incorporate pi+ ->mu+ ->e+ decays. (2) Sakuda reports the schedule for muon and LG. (a) LG: This week, the readout electronics modules (NIM sum modules, HV distributors, FASTBUS ADC's, ~1000 channels) were moved from TOPAZ to VENUS storage room. LG counters will be dismounted from TOPAZ next year. TOPAZ muon filters will be used for radiation shield. (b) Muon chambers: All the responsibility for muon chambers (7000 ch) has been transferred from VENUS to neutrino group. At present, VENUS sits at the TRISTAN beam line. At the beginning of next year, VENUS will be moved from the beam line to the assembly area. All muon chambers and muon filters (Fe 10 cm thick) will be dismounted and stored in the garage during February and April next year. Shifts will be assigned on us for at least one month. Currently, we order 50 jigs to transfer 10-20 chambers and store them. We must complete the specifications for the dismounting procedure by November (->open tender). All readout electronics (Preamps, TKO modules) are already reserved for us. (3) Water/SCIFI detector Chikamatsu summarized the results from the meeting at Nagoya university on September 30 (See Minutes of E362 meeting at Nagoya Univ). What was decided at Nagoya: Nishikawa will order raw fibers (SCSF78 0.5mm diameter or 0.8mm) of about 100km to Kuraray. He also orders one IIT within this year. Nagoya group will help us make the fiber sheets (1m wide, 1.5m long and 10-20 layers) next year. Discussion on what we should do next year: We need 0.2-1 GeV pi+/proton beams and try to measure position resolutions, dE/dx and range using proto-type water/SCIFI detector. If possible, we can even measure pi+ p -> pi+ p reactions, whose kinematics is similar to nu_mu n -> mu- p (QE) reaction. Thus, we can study vertex resolution etc. These studies are very much suited for master thesis. Besides proto-type detector, we must establish the specifications for the fine-grain detector (Water/SCIFI, LG, muon) within next year (1996) in order to start an experiment in 1998-1999. Sakuda suggests that Neutrino group ask the KEK Mechanical Engineering Center for help officially. This is the way the experimental groups having no engineers build big detectors at KEK. (4) Kakenhi application Nishikawa explains that we must obtain money for building the front detector from Kakenhi (Deadline= the end of this month). Nishikawa asks Kobe group (Hara, Aoki, AT.Suzuki) and Tamura to come to KEK on October 15 to discuss the details of the Kakenhi application. (Corrections on October 12 by Nishikawa: He himself visits Kobe on October15. and discusses on Kakenhi with Hara, Aoki and Suzuki.) (5) It is agreed that from now on Sakuda summarizes the minutes of the E362 front-detector meeting and distrubute it to all collaborators via E-mail. ----------------------- We had another short meeting after the previous meeting. E362 MEETING Date: 19:00-20:00, October 6, 1995 Place: KEK R225 Subject: Kakenhi Present: Nishikawa (INS), Nakamura, Sakuda (KEK), Tamura (Okayama) Nakamura will explain the abstract of the neutrino experiment to the KEK Mechanical Engineering Center and ask their support, showing them how innovative a water/SCIFI detector is from a standpoint of the engineers. We need to prepare interesting articles and figures. Nakamura/Nishikawa define the topics for Kakenhi applications to build a front detector. (1) Nishikawa (INS), (2) Kobe group, (3) Niigata group and (4) Okayama group. (I do not write the details here.) (End of the meeting) [Memo by Sakuda]